1. Field of the Invention
The present invention concerns a saw-toothed wire with a foot portion and a plurality of teeth arranged in linear sequence along the wire, each tooth issuing from the foot portion and ending in a single point; a process and apparatus for the manufacture of saw-toothed wires of this kind; and the use of saw-toothed wires of this kind for the processing of textile fibers.
All-steel card clothings made of a plurality of saw-toothed wires of the kind described above that are mounted parallel to each other on a carrier base have almost totally replaced the originally used needle-toothed card clothings in the processing of textile fibers. One reason for this is that all-steel card clothings of this kind are more wear-resistant and, as a consequence, offer the possibility of increasing the processing speed; another reason is the fact that saw-toothed wires of this kind are comparatively simple to manufacture.
2. Description of the Related Art
A state-of-the-art apparatus for manufacturing saw-toothed wires of the kind described at the beginning is shown in FIG. 4. This apparatus has a feed mechanism 410 mounted on a machine bed 400, by which a profile wire 450 is advanced along a given travel path 454. For this purpose, the profile wire 450 is clamped tight between two feed rollers 418, one of which is driven to turn about a rotational axis 420 that is perpendicular to the given travel path 454.
For working the profile wire 450, there is further a machine tool 430 mounted on the machine bed. This machine tool 430 comprises a spindle 436 running in bearings in a spindle stock 434 and driven by a 3-phase AC motor 432 to rotate in the direction shown by the arrow 437. A blanking tool holder 438 is mounted on the front end of the spindle 436 in a rotationally fixed connection. A blanking tool 440 that is mounted on the blanking tool holder 438 and works together with a blanking die 442 of the machine tool 430 provides the means for producing saw-teeth by blanking material-free portions out of the profile wire 450. The 3-phase AC motor 432, the spindle stock 434, the spindle 436 and the blanking die 442 are mounted together on a base plate 444 which can be swiveled in increments of 5.degree. relative to the machine bed 400 and the feed mechanism 410, as indicated by the graduation marks of the angular scale 446.
Mounted at the front end of the spindle 436 is a bevel gear 412. This bevel gear 412 meshes with a bevel gear 414 that is attached in a rotationally fixed connection to that end of a worm gear that faces the machine tool. Thereby, the worm gear is made to turn about a rotational axis whose position is fixed in relation to the machine bed 400 and the feed mechanism 410. This rotation is transferred to a gear that meshes with the worm gear 416 and turns about the rotational axis 420 extending perpendicular to the given travel path 454. This allows the pair of feed rollers 418 to be driven by the 3-phase AC motor 432 via the worm gear 416, the bevel gear 414, the bevel gear 412 and spindle 436. This drive mechanism assures that the profile wire 450 is advanced each time by an equal feed interval in the direction indicated by arrow 452 between the individual work steps performed by the blanking tool 440.
Accordingly, the apparatus shown in FIG. 4, using only one drive motor and one machine tool, provides a particularly simple means of producing saw-toothed wires with a constant pitch, i.e., a constant interval between the points of consecutive teeth. The shape and pitch of the teeth of the saw-toothed wire produced in this manner depend on the position of the base plate 444 relative to the machine bed 400 and also on the feed mechanism 410, the blanking tool being used, and the transmission ratio effectuated by the worm gear 416 in combination with the gear that turns about the rotating axis 420.
When saw-toothed wires made with equipment of the kind shown in FIG. 4 are used in the processing of textile fibers, one observes, particularly at high processing speeds, an increase in damaged staple fibers and accumulations of non-aligned fibers, especially of short fibers (pilling effect).